# KnockKnock for Mac

> See what's persistently installed.

KnockKnock lists launch agents, extensions and login items so you can spot software that starts itself.

## Facts

- Price: Free and open source
- Developer: Objective-See
- Category: Security & Privacy
- Website: https://objective-see.org/products/knockknock.html
- Homebrew cask: knockknock
- Source code: https://github.com/objective-see/KnockKnock
- License: GPL-3.0
- GitHub stars: 817
- Last commit: 2026-09-15
- Facts checked: 2026-10-19
- MacWorthy page: https://macworthy.com/apps/knockknock/

## Install

Homebrew:

```sh
brew install --cask knockknock
```

## Questions

### Is KnockKnock free?

Yes. KnockKnock is free and open source under the GPL-3.0 license. The source code is on GitHub at objective-see/KnockKnock.

### Where can I download KnockKnock for Mac?

Download KnockKnock from the developer's website (objective-see.org) and GitHub. MacWorthy links only to official sources.

### Can I install KnockKnock from the Terminal?

Yes. With Homebrew, run `brew install --cask knockknock`.

### What are good alternatives to KnockKnock?

Other security & privacy apps for Mac worth a look are LuLu (open source), OverSight (open source), Secretive (open source) and Little Snitch (one-time purchase).

## Alternatives in Security & Privacy

- [LuLu](https://macworthy.com/apps/lulu/): The free, open-source outbound firewall. (Open source)
- [OverSight](https://macworthy.com/apps/oversight/): Know when your mic and camera turn on. (Open source)
- [Secretive](https://macworthy.com/apps/secretive/): SSH keys that never leave the Secure Enclave. (Open source)
- [Little Snitch](https://macworthy.com/apps/little-snitch/): See and control every network connection. (One-time purchase)
- [Strongbox](https://macworthy.com/apps/strongbox/): KeePass and Password Safe, made native. (Free + Pro)
- [Tailscale](https://macworthy.com/apps/tailscale/): A private network for all your devices. (Free + Pro)

## Collections

- [Privacy first](https://macworthy.com/collections/privacy-first/)

Tags: malware, open source